Salisbury Police raided an apartment on Lincolnton Road Monday afternoon and took four people into custody, authorities said.
Officers raided a duplex at 719 Lincolnton Road shortly after 1 p.m., using a dummy grenade that caused a loud noise heard for several blocks. Police seized crack cocaine during the investigation, authorities said.
Salisbury High School was on code yellow lockdown for about 20 minutes during the police activity as a precaution, principal Kathy McDuffie said.
During the lockdown, all of the school’s doors were locked and students were not allowed to leave the building, but classes continued as usual, said school spokeswoman Rita Foil.
It was the second time on Monday that schools within the Rowan-Salisbury School System were on lockdown. Earlier in the day, North Rowan High, North Rowan Middle and North Rowan Elementary schools were placed on lockdown after Spencer Police were searching for suspects involved in a break-in at a home on Pineview Drive.
Police seized crack cocaine from the apartment.
Police charged the following:
• Shannon O’Neil Borders, 29, of the 700 block of Lincolnton Road, Salisbury, with felony manufacture, sell, deliver or possess a controlled substance within 1,000 feet of a school; and felony possession with intent to manufacture, sell and deliver a scheduled II controlled substance. He has since been released from the Rowan County Detention Center under a $50,000 secured bond.
• William A. Turner, 37, of the 300 block of West Harrison Street, Salisbury, with felony possession of a scheduled II controlled substance. He was issued a $10,000 secured bond. He has since been released from the Rowan County jail.
• Jericho White, 21, of the 400 block of East Fisher Street, Salisbury, with felony possession of a scheduled II controlled substance. He has since been released from the county jail under $2,000 secured bond.
• Ryan Scott Gore, 27, of the 1300 block of Julian Park Circle, Salisbury, with felony possession of a scheduled II controlled substance. He was issued a $2,000 secured bond and has since been released from the county detention center.

Contact reporter Shavonne Potts at 704-797-4253. Reporter Emily Ford contributed to this story.